physics EM repost
posted by Spencer .
Magnetic resonance imaging needs a magnetic field strength of 1.5 T. The solenoid is 1.8 m long and 75 cm in diameter. It is tightly wound with a single layer of 2.50mmdiameter superconducting wire.
What size current is needed?
Thanks in advance

http://www.pa.msu.edu/courses/2001spring/PHY232/lectures/ampereslaw/solenoid.html
all you have to figure is the number of turns, you are given diameter and length. 
to find N is it L/2d? length being length of solenoid and d is diameter of the wire or solenoid?

ok i got it finally. thanks

good. but actually, N=L/d